What is it?
Linux, or GNU/Linux, is an Operating System capable of replacing Microsoft Windows on the desktop, and being run as a server in your datacentre. It provides thousands of applications and services, frequently available at no cost, and with source code available for quality assurance. Linux is freedom expressed in its open philosophy.
What's in it for me?
There are lots of advantages: cost, adaptability, freedom from vendor lock-in, and a huge selection of free software to name but a few.
Linux is probably the most actively developed operating system you can install on your computer, or in your server room. The work put into it shows in terms of stability and features.
How do I get started?
If you are starting out, or just want to see what it is like, you will probably want to try one of the excellent 'Live CD' distributions. These are versions of Linux which do not require an installation, but instead works directly from CD. I'd recommend Knoppix.
Generic PCs should work, though if you are buying, it is a good idea to confirm that you buy what is known to work especially when it comes to graphics cards supported under X Windows.
That said, most hardware works, and Linux enjoys extensive backing from major manufacturers, most notably IBM and Dell.
It is generally wise to avoid any hardware using SiS chipsets though.
To decide on a Linux flavour, browse the following links: